Zayn: He massages you as you study/do your homework so you're nice and relaxed. He loves english so, he may stop to help you out, and maybe actually do it for you when you're too stressed.
Liam: He likes making flashcards with you. Each answer you get right, there's a reward on the other side where the answer is. Usually it's a quick peck on the lips, forehead, cheek, etc. But, let's just say sometimes it gets a little heated. ;)
Niall: You both L O V E eating, so he'll ask you a question, usually with food in his mouth, and if you get it right, he'll toss a small food in your mouth (such as a grape, m&m, skittle) and you'll continue on until you're homework/studying is done.
Louis: He likes just watching you do what you do, if you need help, he'll usually tweet it, or DM it to a fan for interaction, and to make someone happy. But usually, he enjoys watching you as he feels your concentration face is gorgeous.
Harry: Let's just say he doesn't.. at all. Hazza gets really jealous seeing that your homework is getting more of your attention that he is. So, he tries to distract you by flirting, kissing. Only to be rejected, then whimpering about it later.